The present invention relates generally to input devices and more particularly to direction switches.
As a general rule, portable devices, such as radiotelephones and computers, continue to shrink in size and to be configured in small compact packages (i.e., xe2x80x9cpocketxe2x80x9d sized radiotelephones). Recent radiotelephones have incorporated a variety of new features ranging from optional communication services, including Internet access, through videogames. As a result, menu structures of such devices typically become more complex. Such communication device applications, as well as devices such as laptop computers and portable games, may utilize multidirectional switches, such as 4-way switches. A select switch may be provided apart from, or integrated with, the pressure sensitive switch.
Various known approaches to pointing devices include a joystick, a mouse and a trackball. A mouse and a trackball typically use electromechanical or optical systems to convert a rotational motion of a ball to a linear motion of a cursor. Joysticks typically include an array of digital contact switches that detect when the joystick is moved in a particular direction. Various pointing devices detect both direction and pressure by sensing the magnitude and direction of a force applied to the pointing device. Examples of pressure sensitive pointing devices are described in U.S. Pat. Nos. 5,231,386 (xe2x80x9cthe ""386 patentxe2x80x9d) and 5,828,363 (xe2x80x9cthe ""363 patentxe2x80x9d).
The ""386 patent is directed to a keyswitch-integrated pointing assembly in which a plurality of substantially planar force sensing elements are disposed on a planar surface adjacent a keyswitch on a keyboard. The device thus combines a keyswitch with force sensing resistor elements. A rubber dome sheet extends between the actuator element and the force sensing elements to disperse applied forces smoothly. The forcing sensing resistors are pre-loaded to bias the elements into a substantially linear operating region when no force is applied to address problems with stability associated with non-linear operating ranges of force sensing resistors.
The ""363 patent is directed to another type of force-sensing pointing device utilizing force sensing resistors to detect the magnitude and position of an applied force. A connector, such as an elastomeric adhesive, maintains a force transfer member in contact with the force sensing resistors. A related product is available from Interlink Electronics of Camarillo, Calif. as described in the associated High-Precision MicroJoystick Integration Guide. This product is described as being suited to computer-cursor control and as providing both a click (select switch) function and cursor speed control responsive to the amount of an applied pressure.
The present invention provides pressure sensitive switching devices which may facilitate assembly and provide higher tolerance for variation in alignment of components while still providing for pressure sensitive direction detection. The devices of the present invention may be particularly advantageous when integrated into devices, such as cellular radiotelephones, to provide a user interface to facilitate user navigation through increasingly complex menu structures. In various embodiments, the present invention may detect pressure in addition to two and, preferably, at least four directions. In particular embodiments, the devices of the present invention may provide switching devices having a plurality of trace grid areas located, for example, on a printed circuit board and actuated responsive to pressure applied by a user through a poly-dome layer where increased pressure results in contact with a greater number of the traces in respective grids. Alternative embodiments include trace patterns which are substantially circumferentially arranged in patterns configured to detect user input. A select switch is included in various embodiments of the present invention.
In embodiments of the present invention, pressure sensitive direction devices are provided. A first member includes a plurality of contact regions, each of the contact regions including trace lines, the trace lines being formed from one of a conductive and a resistive material. A second member is positioned adjacent the first member, the second member including a plurality of deformable switch regions. The plurality of deformable switch regions are positioned adjacent the plurality of contact regions and have an inner surface on a side adjacent the first member. The deformable switch regions include a connection layer on the inner surface thereof. An actuator has contact regions positioned adjacent an outer surface of the deformable switch regions. The contact regions of the actuator deform the switch regions responsive to pressure on the actuator in the vicinity of the contact regions of the actuator to compress at least one of the deformable regions so as to bring the connection layer into contact with a number of trace lines of the contact regions of the first member, the number of trace lines being proportionate to the pressure on the actuator.
In other embodiments of the present invention, the connection layer is formed from the other of the conductive and the resistive material so that one layer is conductive and the other is resistive. Preferably, the first member includes at least three contact regions and the contact regions are positioned in spatially displaced locations on the first member. The trace lines may include a first grid of trace lines electrically coupled to a first output and a second grid of trace lines electrically coupled to a second output. The deformable switch regions may be spatially displaced domes formed in the second member. The domes may be concave when viewed with reference to the inner surface of the second member and the contact regions of the actuator may be convex when viewed with reference to the inner layer of the actuator with the convex contact regions substantially aligned with the domes. A keycap layer may be positioned adjacent an outer layer of the actuator to provide a user contact surface. The first member may be a printed circuit board and the second member may be a poly-dome layer. The resistive material may be a resistive ink and the actuator may be formed of a deformable non-conductive material.
In further embodiments of the present invention, the pressure sensitive direction device includes a select switch positioned in the pressure sensitive direction device. The select switch may include a switch contact region associated with the first member and electrically isolated from the plurality of contact regions and a conductive dome positioned adjacent the switch contact region. A select actuator may be positioned above the conductive dome and have a first position when unloaded not placing the conductive dome in contact with the switch contact region and a second position when loaded placing the conductive dome in contact with the switch contact region. The conductive dome may be a metal dome and the second member may include an aperture configured to allow the metal dome to pass through the second member. Alternatively, the second member may be a unitary member formed from a non-conductive material and including the conductive dome and the plurality of domes and the conductive dome may include a conductive material layer on the inner surface of the conductive dome. The switch contact region may be positioned between the plurality of contact regions and the conductive dome may be positioned between the plurality of domes.
In other embodiments of the present invention, the trace lines in each of the plurality of contact regions are 3 or more separate trace lines and the trace lines and the connection layer comprise a conductive material. The separate trace lines are positioned adjacent each other so as to provide a digital signal output having an increasing number of the separate trace lines being selected by contact with the connection layer responsive to increasing pressure on the actuator. An electro-luminescent panel may be formed with the poly-dome layer.
In further embodiments of the present invention, a pressure sensitive direction device is provided. A first member includes a plurality of circumferentially displaced signal contact regions and a plurality of output contact regions interspersed with the plurality of signal contact regions. A second member has a connection region positioned adjacent the signal contact regions and output contact regions of the first member. The connection region of the second member is made from a deformable material having an associated conductivity that is responsive to pressure applied to the second member. The plurality of signal contact regions includes a first group associated with a first direction and a second group associated with a second direction and a larger number of the first group are positioned in a region of the first member associated with the first direction than in other regions of the first member and a larger number of the second group are positioned in a region of the first member associated with the second direction than in other regions of the first member to provide an increased conductivity electrical path between the first group and the output contact regions responsive to pressure applied to the second member adjacent the region of the first member associated with the first direction and an increased conductivity electrical path between the second group and the output contact regions responsive to pressure applied to the second member adjacent the region of the first member associated with the second direction. The increased conductivity may be a function of the pressure applied to the second member.
In other embodiments of the present invention, the plurality of output contact regions are electrically connected. The second member may be made from a material selected from partially conductive silicon rubber or Santoprene(trademark). The material of the second member may include conductive particles distributed in the material to provide a range of conductivity between one of the plurality of signal contact regions and an adjacent one of the plurality of output contact regions from between about 5 ohms and about 100 kilo-ohms when a portion of the second member contacts the one of the plurality of signal contact regions and the adjacent one of the plurality of output contact regions. The conductivity between the one of the plurality of signal contact regions and the adjacent one of the plurality of output contact regions is a function of the pressure applied to the second member. The conductive particles may be carbon particles. A spacer may be positioned between the first member and the second member to position the connection region offset from the plurality of signal contact regions when pressure is not applied to the second member. The second member may include a joystick or a toggle top on a face thereof away from the first member.
In other embodiments of the present invention, the plurality of signal contact regions further includes a third group associated with a third direction and a fourth group associated with a fourth direction. The first and second group correspond to a first axis and the third and fourth group correspond to a second axis substantially perpendicular to the first axis. The plurality of circumferentially displaced signal contact regions may be arranged in a substantially circular pattern wherein one of the output contact regions is positioned substantially on the first axis in the region of the first member associated with the first direction and positioned between two of the signal contact regions of the first group and one of the output contact regions is positioned substantially on the first axis in the region of the first member associated with the second direction and positioned between two of the signal contact regions of the second group. One of the output contact regions may be positioned substantially on the second axis in a region of the first member associated with the third direction and positioned between two of the signal contact regions of the third group and one of the output contact regions may be positioned substantially on the second axis in a region of the first member associated with the fourth direction and positioned between two of the signal contact regions of the fourth group.
In addition one of the signal contact regions of the first group may be positioned in the region of the first member associated with the third direction on an end thereof adjacent the region of the first member associated with the first direction and one of the signal contact regions of the first group may be positioned in the region of the first member associated with the fourth direction on an end thereof adjacent the region of the first member associated with the first direction. One of the signal contact regions of the second group may be positioned in the region of the first member associated with the third direction on an end thereof adjacent the region of the first member associated with the second direction and one of the signal contact regions of the second group may be positioned in the region of the first member associated with the fourth direction on an end thereof adjacent the region of the first member associated with the second direction. A backlighting source may be positioned between the first member and the second member.
In other embodiments of the present invention a pressure sensitive direction device is provided. A first member includes a plurality of adjacent circumferentially extending contact regions. A second member has a plurality of radially extending ridges positioned adjacent and extending substantially across widths of the plurality of contact regions, the plurality of ridges comprising a deformable material having an associated conductivity that is responsive to pressure applied to the second member. The plurality of contact regions have varying widths in the vicinity of the plurality of radially extending ridges to provide a respective conductivity between each of the plurality of contact regions responsive to pressure applied to the plurality of radially extending ridges and as a function of the relative widths of the plurality of contact regions in the vicinity of the plurality of radially extending ridges.
In further embodiments, the plurality of contact regions are each formed in a spiral pattern with the spiral patterns defining each of the plurality of contact regions beginning at offset angular positions and extending for less than 360 degrees. The second member may be made from partially conductive silicon rubber or Santoprene(trademark). The plurality of contact regions may extend circumferentially substantially around the switch contact region. A spacer may be positioned between the first member and the second member to position the plurality of ridges offset from the plurality of contact regions when pressure is not applied to the second member.